Combination lock mechanism



Jan. 28, 1969 HARRELL I I 3,423,970

COMBINATION LOCK MECHANI SM Sheet g of5 Filed Feb. 23, 1967 J {g /3 nan4 702:

v if .305 19/726544 FIG ,3 4 6 yzrazmer B. G. HARRELL.

Jan. 28, 1969 COMBINATION LOCK MECHANI SM Sheet Filed Feb. 25, 1967 Jan.28, 1969 B. G. HARRELL COMBINATION LOCK MECHANISM Sheet Filed Feb. 23,1967 FIG.6

FIGJI I 7 Claims ABSTRACT OF THE DISCLOSURE A combination lock mechanismhaving a plurality of rotary tumblers actuated by a dial from theexterior of the casing to align the gates in the tumblers so that areversibly movable pawl carried on the inner portion of a locking boltmay be forced by reversing driver means first in a direction to cause afence on the pawl to move into the aligned gates. Entry of the fenceinto the gates will unlock the bolt and allow the pawl to move in adirection to by-pass a stop pin by means of a by-pass slot in the pawl.Upon reversal of the driver means the pawl is shifted to reverse thedirection of movement away from the tumblers to withdraw the pawlprojection from the gates. When the unlocking pressure is removed fromthe bolt a spring will return the bolt to locking position and at thesame time pull the pawl around the stop pin to its starting positionready to again strike the stop pin and prevent unlocking actuation ofthe bolt until the tumblers are again rotated to align the gates in theadjusted position where unlocking of the bolt may take place. During thepawl engagement in the aligned gates the tumblers are angularlydisplaced to a position removed from the initial position where the pawlfence first entered the gates so that reentry of the pawl fence isprevented after the pawl has passed around the stop pin on its movementto the starting position.

This improvement relates to combination type lock mechanisms havingrotary combination discs or tumblers United States Patent and a pivotedbolt that is controlled by a simplified pawl and pawl driving means inassociation with the combination discs.

The combination lock mechanisms heretofore provided have requiredintricate components for scrambling the tumblers each time the lock isunlocked so that the gates are thrown out of alignment to preventsubsequent unlocking operation Without first dialing the propercombination.

The object of this improved lock mechanism is to avoid the complexconstruction of components, to eliminate certain components, and tosimplify the construction of a combination lock without detriment to thesecurity desired which is that of preventing unauthorized actuation.

A further object of this improved lock mechanism is to provide a simplepawl and stop means that will prevent picking the lock by feel of thetumbler gate positions.

In accordance With the foregoing brief description of the improved lockmechanism as preferred'construction will be hereinafter disclosed inconnection with the accompanying drawings, wherein:

FIG. 1 is afragmentary front elevation of the present lock for a doorpost and door lock actuation rod to illus trate one embodiment of theinvention;

FIG. 2 is a greatly enlarged sectional view taken at line 22 in FIG. 1of the lock mechanism;

FIG. 3 is a view taken at line 33 in FIG. 2 with the pawl in itsstarting position;

FIG. 4 is a view similar to FIG. 3, but wherein the pawl fence hasentered the gates in the tumblers;

FIG. 5 is another view similar to FIG. 3 but with the 3,423,970 PatentedJan. 28, 1969 bolt moved and the mechanism placed;

FIG. 6 is yet another view similar to FIG. 3 but with the bolt and pawlpositioned for the return of the pawl about the outside of the stop pin;

FIG. 7 is a view similar to FIG. 6 to show one of the two positions ofthe pawl spring, the other position being that of FIG. 6;

FIGS. 8 and 9 are respectively side and end views of the bolt used inthe mechanism of FIG. 2;

FIGS. 10 and 11 are respectively top and side views of the pawlassociated with the bolt of the preceding views; and

FIG. 12 is a plan view of a passkey actuated cam member by which themechanism heretofore shown may be unlocked without having to work thetumblers into alignment.

Referring to FIG. 1, the present combination lock mechanism 14 is shownmounted on a door or movable part 15 (such as a locker door) with itslocking bolt 16 engaged in a notch 17 in a slide rod 18 carried by thedoor. The door cooperates with a fixed frame or part 19 (such as alocker frame member having a suitable notch to receive a catch 19' thathooks into the notch). The lock mechanism includes a rotary dial or knob20 and an escutcheon plate 21 which holds the dial in position.

Turning now to FIGS. 2 and 3, the mechanism combines a combination lockwith a cylinder lock mounted in a housing or case 22 having flanges 23and 24 at opposite sides and an enlarged chamber 25 of generallyrectangular shape. The chamber 25 opens at its central area into a well26 having a suitably shaped bore 27. The case 22 is closed by a cover 28which is substantially coextensive with the case flanges 23 and 24. Thecase 22 and cover 28 are positioned against the back side of the door orpart 15, and suitable holes in the part 28 admit the insertion ofmounting studs 29 which with threaded nuts 30 secure the face plate 31at the front of part 15 and the case 22 at the back of part 15.

The lock case operatively receives a key operated cylinder lock 32 (FIG.2) mounted in the bore 27 of well 26, and a tubular key receiving shaft33 extends outwardly from the plug cylinder 32 through the chamber 25 tothe cover 28. The cylinder 32 has the usual retractable prongs (notshown) which control rotation and it is retained in position axially ofthe bore 27 by a base plate 34 located by and secured in the bottom ofthe case chamber 25 by a plurality of rivet 0r headed elements shown at35. Between the base plate 34 and cover 28 there are arranged on thetubular shaft 33 in stacked relation the'following parts: adjacent thebase plate 34 is a key operated cam plate (FIG. 12), next a compressionspring 36 is placed on the cam plate 80 to support the bottom mosttumbler disc 37. A spacer 38 is placed on the tumbler 37 and the middletumbler disc 39 is placed thereon, followed by a second spacer 40 andthen the topmost tumbler disc 41 is placed next. A drive tube 42connected to the tumbler 41 is received over the upper end of thetubular shaft 33, and the dial 20 is then mounted on the outer end ofthe drive tube 42. All of these parts are of known construction and areheld in position by the compression spring 36. The tumblers 37, 39 and41 are each formed with gate notches, such as the gate notch 43 shown inFIG. 3 for the top tumbler 41, and the peripheral edges of the tumblersare given an undulated shape to discourage picking attempts, as is wellknown.

Looking at FIGS. 2 and 3, it can be seen that the locking bolt 16 hasone end 46 mounted on a pivot pin 47 securely positioned in the case 22,the other end 48 of the bolt 16 extends about the tumblers 37, 39 and 41toward the opposite side from the pivot pin 47. As can correspondinglydis- 3 be seen in FIGS. 8 and 9 the locking bolt 16 is made up of a topplate 49, a center plate 50' and a bottom plate 51 of wider dimensionthan either plate 49 or 50. Thus, plate 51 has an inner circular edge 52that is offset from the edge 53 of the two plates 49 and 50. The plates49, 50 and 51 are held in assembly by rivets 54. The locking bolt 16(FIG. 3) is urged into its locking position by the spring arm 55. Thebody 56 of the spring is mounted about pin 47, and the opposite arm 57presses against the interior wall of the case chamber 25.

The arm 48 of the bolt 16 is apertured at 58 (FIG. 8) in plates 49 and51 to receive a pivot element 59 (FIG. 3) that operatively connects thelug 60 (FIGS. and 11) of a pawl 61 between plates 49 and 51. The pawl 61has an enlarged body 62 with a notch 63 formed in its bottom edge 64,and a fence portion 65 provided near the bevelled end 66 opposite thelug 60. The pawl body 62 is slotted at 67 to receive one arm 68 of apawl actuating or drive means, such as a spring 69 mounted or coiledabout the head end of the pivot element 59. The opposite arm 70 of thespring is formed with a looped end 71 which is free to engage at certaintimes the wall surface 72 and the wall surface 73 of the case chamber 25to shift the direction of reaction of spring arm 68 upon the pawl 61 aswill be set forth in more detail presently. The pawl 61 normallycooperates with stop pin 74 carried in the bottom of the case 22adjacent the position where the tumbler gates are intended to come intoaligned positions, and where the pawl fence 65 may enter the alignedgates. The wall of the case chamber 25 adjacent the stop pin 74 isrecessed at 75 to allow for the pawl to pass between the pin 74 and therecess 75.

It is noted that when the tumbler gates or gate notches are misalignedthe pawl fence 65 is prevented from moving inwardly of the peripheriesof the tumblers and force applied on the bolt face 76 will only move thebolt 16 a very short distance to bring the bevelled face 66 of the pawlagainst the stop pin 74 to block or stop unlocking action of the bolt.Normally in the locked position the pawl spring 69 has its active end 71engaged on wall surface 72 so that the arm 68 is stressed to pivot thepawl 61 in a clockwise direction (FIG. 3) about the pivot 59. At thistime the fence rides on the peripheries of the tumblers 37, 39 and 41.When the end 71 of the pawl spring shifts with the locking bolt 16 sothat it engages the wall 73 in the case 22 it changes the direction offorce exerted by the arm 65 upon the pawl 61, and the pawl wants topivot about pin 59 in a counterclockwise direction. The reversal of theforce eifect exerted by the pawl drive means is an important feature ofthe mechanism.

Combination lock operation Having described above the components, partsand mechanism of the present lock assembly, reference will now be madeto the views of the drawings, and particularly FIGS. 3 to 7 inclusive.

FIG. 3 illustrates the combination lock mechanism in which the tumblers37, 39 and 41 have their gate notches, such as notch 43, scrambled so asnot to be in aligned registration. At this time any force appliedupwardly on the face 76 of the bolt 16 will effect a slight pivotingmovement of the bolt about the axis of the pivot pin 47 which causespawl movement also, until the bevelled face 66 on the pawl 61 strikesthe stop pin 74 of the bolt 16 and is prevented from moving sufiicientlyto permit the slide rod 18 to move upwardly far enough so that thesurface 76 on the bolt 16 will allow the lock rod 18 to movesufliciently for unlocking purposes. During this slight permissivemovement of the bolt 16 the end 71 on the pawl spring arm 70' will notbreak engagement with the wall surface 72, consequently the bolt 16 willbe urged to pivot in a clockwise direction about the axis of the pivotpin 59.

In FIG. 4 it is assumed that the dial 20 has been correctly operablyactuated to relatively rotate the tumblers 37, 39 and 41 so that thegate notches therein will all be in alignment. As this alignment occursthe force exerted on the pawl by the spring arm 68 will cause the pawl61 to pivot in a clockwise direction, without any movement of the bolt16, so that the fence 65 will enter the aligned notches. This actionwill remove the bevelled face 66 on the end of the pawl 61 fromengagement with the stop pin 74, thereby allowing the bolt 16 to pivotwithout obstruction about its pivot 47. The bolt movement in itsunlocking operation is shown by comparing FIGS. 4 and 5 As shown in FIG.5 the bolt 16 has moved into a position where it is almost in a fullunlocked position, and it is noted that in this position the notch 63 inthe bottom edge 64 of the pawl body 62 (FIG. 11) will have moved intoalignment with the stop pin 74. Concurrently with the alignment of thenotch 63 and stop pin 74, the end 71 on the pawl spring arm 70 will haveshifted its operative position from engagement on the wall surface 72 toengagement on the wall surface 73 in the chamber 25. The shifting of theengagement of the end 71 on the spring arm 70 will shift the directionof spring pressure applied by the opposite arm 68 on the pawl 61 andcause the pawl 61 to swing in a counterclockwise direction to theposition shown in FIG. 6. The sequence of motion of the pawl 61 is shownpartly in phantom outline in FIG. 6 and its fully retracted position isshown in full line.

In the motion of the locking bolt 16 between the positions shown inFIGS. 4 and 5, it will be understood that the tumblers 37, 39 and 41will be rotated in unison to a new position (FIG. 5) where they will beleft at the time the pawl spring shifts its direction of force on thepawl 61 and causes the pawl to move to the fully released position shownin FIG. 6. The locking bolt 16, it is noted, is at all times subject tothe pressure from the arm 55 of a coil spring body 56. The spring arm 55constantly urges the bolt 16 to pivot in a counterclockwise direction soas to normally want to assume its locked position.

In referring to FIG. 7 it can be seen that the spring arm 55 has causedthe locking bolt 16 to move in a counterclockwise direction, and indoing this the pawl 61 is displaced from the position shown in FIG. 6 toa position as shown in FIG. 7 where the fence 65 thereon will now be outof registration with the gate notches in the several tumblers, and thegate notches 43 in the tumblers 37 and 39 have a shape different fromthe gate notches 43 in the tumbler 41. The relatively different shapedgate notches will prevent the fence 65 from reentering, and the amountof angular displacement experienced by the tumblers during the unlockingaction of the bolt 16 will likewise prevent the fence 65 fromautomatically registering with the gate notches. Hence, once the bolt 16has returned to its normal starting position (FIGS. 3 and 7) the pawl 61will thereafter be blocked from allowing the bolt 16 to move to unlockbecause its bevelled face 66 will strike the stop pin 74. It is alwaysrecommended when using a combination lock, to give the dial an extraspin when the mechanism is returned to its intended locked position sothat there will be very little likelihood of leaving the gate notches inthe tumblers near the position of alignment. The precaution makes itnecessary to have the proper combination whereby the tumblers at somefuture time can be again brought into gate notch alignment.

The foregoing operation of the combination lock mechanism has set forththe important characteristics wherein the pawl drive means or spring 69is made to perform two functions by means of changing its direction ofapplied force. In FIG. 4 the pawl spring 69 is in its position to forcethe pawl 61 to move in a clockwise direction for unlocking the bolt 16.The unlocking action of the bolt 16 causes the pawl 61 and the spring 69to move through intermediate positions of FIGS. 5 and 6 where the pawl61 displaces the tumblers and then leaves the tumblers and passesoutwardly around the backside (referring to the relative position of thetumblers and the stop pin) of the stop pin 74 due to the change ofdirection of the pawl spring 69 and particularly of the spring arm 68.When the pawl 61 reaches the position of FIG. 6, the pawl and the boltwill be in position to return to the starting locked condition as isshown in FIGS. 7 and 3. FIG. 7 shows an intermediate position and FIG. 3shows the normal locked position of the components and parts.

Cylinder lock operation It has been heretofore pointed out that thepresent lock mechanism includes a cylinder lock 32 mounted in the well26 of the case 22. In order to operate the cylinder lock 32, the tubularshaft 33 which extends through the chamber 25 of the case 22 is formedwith a suitable slot 77 for the reception of a key (not shown) throughthe center of the dial 20. The insertion of the key in the slot 77 willdraw in the projecting prongs and permit the cylinder 32 to be rotatedin the well 26, and rotation of the tubular shaft 33 will cause the keycam 80 (FIG. 12) to be rotated because the key cam 80 is formed with apair of nibs 78 that fit into longitudinal and similarly shaped grooves79 (FIG. 2) in the opposite sides of the tubular shaft 33. Thus, the keycam 80 is keyed to the tubular shaft 33 and may be driven by it when theproper key is inserted in the slot 77. The purpose for the key cam 80 isto permit only persons who have authorized possession of the proper keyto bypass the combination lock mechanism and unlock the bolt 16. This isaccomplished by turning the key slot 77 from the position shown in FIG.6, where the cam lobe 80 is in corresponding position, to the positionshown in FIG. 7 where the cam lobe 80 has been moved approximately 90 ina clockwise direction to strike the surface 81 (FIG. 11) on the pawlbody 62. The engagement of the cam lobe 80 with the surface 81 on thepawl body will cause the pawl 81 to be lifted from the full lineposition of FIG. 7 to the fragmentary dotted line view of FIG. 7 whereit can be seen that the bevelled face 6-6 on the outer end of the pawlhas been lifted above the stop pin 74. This is all that is required tounlock the bolt 16.

The foregoing description has set forth the components and parts of theimproved combination lock mechanism, and has set forth the cooperationbetween a combination lock mechanism and a cylinder lock mechanism foreffectively bypassing the combination lock mechanism when it is desiredto do so under authorized conditions. There has also been disclosed acombination lock mechanism that has an organization of parts andelements which provide a unique and novel way of utilizing a pawl forscrambling the set of tumblers and for preventing unlocking action ofthe usual locking bolt. Furthermore, there has been herein disclosed astructure for effective operation of a combination lock pawl for twodifferent purposes by the unique incorporation of a driving member thatis able to drive the pawl in opposite directions in response to movementof the usual locking bolt. It is, of course, understood that changes andmodifications may occur to those skilled in this art, and it is intendedto cover such modifications and changes within the spirit and scope ofthe annexed claims.

What is claimed is:

1. In a combination lock, a case, a locking bolt pivotally mounted insaid case and having a part extending outwardly of said case, said boltbeing movable between locking and unlocking positions, a pawl pivotallymounted on said bolt within said case and movable with and relative tosaid bolt, a stop element in said case in position to block movement ofsaid pawl with said bolt and prevent movement of said bolt intounlocking position, a plurality of combination discs operable in saidcase to normally maintain said pawl against movement relative to saidbolt but adjustable to permit such relative movement, and drive meansconnected to said pawl having a first position urging said pawl to movein one direction relative to said bolt upon adjustment of saidcombination discs and bypass said stop element, said drive means beingmovable, in response to bolt movement into unlocking position, into asecond position to reverse the urging motion of said pawl relative tosaid bolt to cause said pawl to bypass said stop element upon boltreturn movement into locking position.

2. The combination lock set forth in claim 1 wherein said drive meanshas one arm engaged on said pawl and a second arm in position to engagedifferent portions of said case in response to said bolt being inlocking and unlocking position, said drive means engagement with saidcase developing its urging effect upon said pawl.

3. The combination lock set forth in claim 1 wherein said pawl is formedwith a surface engage-able on said stop element to block bolt movementtoward unlocking position, and said pawl is formed with a notch inposition, upon said bolt reaching its unlocking position, to permit saidpawl to pass said stop element upon reverse motion of said pawl.

4. The combination lock set forth in claim 1 wherein said drive means isa spring member having one arm engaged on said pawl and having a secondarm extending into engagement on said case, movement of said bolt andpawl between bolt locking and unlocking positions causing said secondarm to stress said first arm to drive said pawl.

5. The combination lock set forth in claim 1 wherein said plurality ofcombination discs are provided with gate notches movable into alignmentupon combination disc adjustment, and said pawl is provided with a fencein position to be driven into engagement with said aligned gate notchesby said drive means, said fence displacing said discs upon bolt movementinto unlocking position and said drive means upon movement into saidsecond position reversing the drive on said pawl to extract said fencefrom said gate notches and prevent re-engagement thereof.

6. In a combination lock, a case, combination tumbler discs operable insaid case and having gate notches movable between a first positionpreventing unlocking and an adjusted aligned second position where thelock may be unlocked, a manual control member projecting from said casepermitting said tumbler discs to be moved out of said first positionsuch that said gate notches are moved to said adjusted aligned secondposition, a bolt operably mounted in said case for movement betweenlocked and unlocked positions, spring means normally urging said boltinto its locked position, and a reversible power operated pawl carriedby said bolt, said pawl having a fence thereon, said pawl and fencenormally in the second position of said tumbler discs being urged bysaid pawl into said aligned gate notches to permit bolt movement towardits unlocked position and tumbler disc movement into locked position,movement of said bolt into unlocked position causing said pawl toreverse its powered operation and withdraw its fence, said bolt springreturning said bolt to its locked position.

7. The combination lock set forth in claim 6 wherein the reversiblepower for said pawl is a spring having one arm engaged on said pawl andanother arm movable in said case to engage different portions of saidcase for changing the direction of spring reaction of said one arm onsaid pawl.

References Cited UNITED STATES PATENTS 1,956,069 4/1934 Hill 702932,775,115 12/1956 Bremer 70133 3,176,486 4/1965 Richardson 70133 MARVINA. CHAMPION, Primary Examiner. EDWARD J. MCCARTHY, Assistant Examiner.

US. Cl. X.R.

